1. Field of the Invention
The present invention relates to an electromagnetic compatibility (EMC) sealing apparatus and related method; and more particularly to an EMC sealing apparatus and method for an empty slot of an electrical enclosure used in computing system environments.
2. Description of Background
It is an industry goal to continuously increase the number of electronic components inside an electronic device. This goal is driven by several key and important reasons. The first and more obvious one is for the convenience of compactness. Compactness allows for selective fabrication of smaller and lighter devices that are more attractive to the consumer. Some of the reasons for such appeal stem from a desire for easier transportation, shipping, installation and storage of such devices. In other instances, when compactness per se is not a driving factor, providing the same number of devices in only a fraction of available footprint allows the remaining space to be filled with more components which will increase system performance and speed. In addition, compactness also allows many of the circuits to operate at higher frequencies and at higher speeds due to shorter electrical distances in these devices. Unfortunately, despite many of the advantages associated with this industry goal, there are several important challenges that have to be overcome by the designers of these systems.
One area where the challenges and advantages provided by such compact densities is increased is in the computer industry. The reliance of many businesses on computers and computer networks in recent years, demands an ever increasing need to provide fast and accurate systems in the smallest and lightest allowable footprint. In a computing environment, whether comprising of a simple personal computer, or a complex system comprising of a number of computers in processing communication with one another, a plurality of printed circuit boards and cards are provided that house many electronic components and even devices.
A particularly challenging area for the designers of these systems is the issue of resolving electromagnetic interference (EMI). As the number of components are increased, electromagnetic leakage concerns continue to grow. This is because every electronic device, emits some form of electromagnetic radiation. If unresolved, EMI can affect system performance, data integrity and speed. Obviously, in larger system environments, the increased number of components that are stored in close proximity to one another, greatly increases the EMI concerns. This is because while such effects can be tolerated when few devices and components exist, the increasing number of components and devices can seriously impact system integrity and performance. This problem is further exacerbated by the improvement in semiconductor devices which allow them to operate at higher speeds, generally causing emission in higher frequency bands where interference is more likely to occur.
Prior art attempts have been made to minimize the interference problem. Electromagnetic compatibility (EMC) requires that emissions from a given device be reduced by shielding or other similar means. Such shieldings are designed not only to reduce emissions from the device itself, but also to reduce sensitivity of the device to external fields such as fields from other devices. One type of such EMI shieldings are EMI gaskets.
In recent designs, it is necessary to use a metallic type of electromagnetic gasket filler to contain EMC emissions in an electrical enclosure in which a device having a printed circuit board or card assembly engaged therewith is absent from a slot of the enclosure, thereby leaving an open and empty slot. However, a common problem with such gaskets are that they do not fully contain EMC emissions when the slot is not populated by an active card assembly. The conventional style EMC gasket filler is configured as a single layer screen allowing escape of EMC energy therethrough. Since the conventional style EMC gasket filler does not fully contain EMC emissions, it doesn't provide suitable EMI protection and may even pose a threat for a potential short.
While the conventional EMC gasket filler solves many of the prior art problems, it is desirable to introduce a mechanism that can contain more, if not all, EMC emissions when a slot of an electrical enclosure used in computing system environments is not populated by an active card assembly. Accordingly, a need exists for a method and apparatus for providing enhanced EMC shielding for an empty slot of an electrical enclosure used in computing system environments. Such an enhanced EMC gasket filler should be mechanically stable to ensure a continuous grounding and designed to facilitate removal and installation thereof. In addition, it is desired that the manufacturing costs for the enhanced EMC gasket filler for shielding an empty slot of an electrical enclosure used in computing system environments be reduced.